


When I said I wanted to shift, I didn't mean this.

by Fanfic_Addict_No_1



Category: Haikyuu!!
Genre: Angst, Atsumu being a good older brother, Atsumu was originally a girl, Minorly canon-compliant, Miya Osamu being raised by Miya Atsumu, More angst, Multi, Self-Insert, Some Fluff, Sorry Not Sorry, The Author Regrets Everything, The Author Regrets Nothing, Their parents die when they are like three, You're in for a wild ride, but does NOT mind the gender change, lots of trigger warnings
Language: English
Status: In-Progress
Published: 2021-01-04
Updated: 2021-01-06
Packaged: 2021-03-15 04:40:26
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 3
Words: 2,271
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28557753
Author URL: https://archiveofourown.org/users/Fanfic_Addict_No_1/pseuds/Fanfic_Addict_No_1
Summary: A 22 year old Psychology major who is really interested in TikTok tries to shift. However, they do not write out a script or safe-word, and is stuck in the Haikyuu!! world as Miya Atsumu until they can find their way back home. However, there's a catch, when they shifted, the Miya Twins were only 3 years old!
Relationships: Eventual Miya Atsumu/Sakusa Kiyoomi - Relationship, Eventual Miya Osamu/Suna Rintarou, other - Relationship
Kudos: 11





	1. Curiosity Killed the Cat

Shifting, huh

If I were to be honest, when I was younger I've always thought about being reincarnated into another world. It didn't matter if it was Harry Potter, Naruto, or The Hunger Games, as long as i had my memories and got to play a major role, it was bound to be interesting. Whenever I daydreamed, I would always think about how I would act in such a situation. Would I be able to be the brave bookworm Hermione Granger and marry Ron? Or would I be able to go through what Sasuke did? I had always assumed I would never know, as all of those characters are fictional and reincarnation may not even be real. However, with this "shifting" thing I may actually be able to live out one of my dreams. It would be better to shift into a safe world first, like the one of Clean Freak! Aoyama-Kun! or Attack On Titan during the time of peace. Deciding on a place proved harder than initially thought. However, after thinking it through the whole day (instead of paying attention to my online classes), I've decided on Haikyuu!!. However, I could never be Hinata or Kageyama, who are really the only players on Karasuno that would be interesting. I could be a pretty amazing Oikawa, but I don't want to have to wear a mask of cheerfullness for the fangirls I will eventually get. I could never actually be friends with Oikawa like Iwaizumi, and no one else from Aoba Johsai is interesting enough. I honestly would never want to replace anyone on Shiratorizawa, and the other Miyagi teams aren't really all that important to the timeline. My personality would be a terrible fit for how the characters are supposed to act in any Tokyo team, so my last hopes are Itachiyama and Inarizaki. I could never be Kimori, and a large part of who Sakusa is, is his mask. Although his and I opinions on germs are mostly the same, I know masks can do more harm then good sometimes and I could never wear one all the time.

...

Inarizaki is a whole other can of worms. I don't want to be a chef or a farmer, so Osamu and Kita are out. If I'm honest, I don't really want to be Aran with the discrimination I may face. Akagi and the rest aren't really that important to the highschool plot. 

...

That really only leaves one player for me. At the moment I kin him, so it can't be that hard... right..?

...This is a terrible idea. I would be terrible. We act completely different and I'm sure that I have fears that he doesn't and vice-versa. There is no way this could turn out well. If I shift into him, i might as well be shifting into Oikawa. Plus I would have to be loud, obnoxious, and fight a lot. I may be studying psycology, but that doesn't mean I'll be able to fool literally everyone from seeing the change in behaivor. Plus, it would be extremely weird for my habits to become his. But.. the idea is very tempting...

Alright. I'll decide this tomorrow. I have work to do, and it won't do itself.


	2. What the Hell?!?

**Summary for the Chapter:**

> The actual story begins

_Fuck_

I must've fallen asleep while typing up that essay. I know I shouldn't have put it off until last night, but I was just so interested in shifting! I mean, how could I not? Travelling to different universes, I guess I wanted to try it more than I thought. Either way, I should try it out soon. Finally opening my eyes, I just about scream in shock. This is definitely _not_ my room. I seem to be on a bunk bed, with a celing fan in the middle of the room at my eye level. Speaking of not being in my room, there's someone breathing on the bottom bunk. They seem asleep, but just in case I slowly roll off the bed. 

_Wait a minute..._

What the hell happened to my body?!? Fucking shit - what- what the fuck. I'm like.. at lease two feet shorter! And.. and.. my chest! What happened to my chest?! What the hell is between my legs?!? 

_Breathe_

This is no time to freak out. I need to stay calm. First step, look at who is on the bottom bunk. Then I can find a mirror or something. Hopefully by that point in time I'm still alive. Silently, I turn to see a little boy in the bunk. A little boy who seems a little bit too familiar. On top of that, everything seems to be fake, like it's in 2-D. This is definitely crossed into an unknown territory. As far as I knew, there was no wayb for anything tom look 2D unless it was on a piece of paper or an electronic. Therefore, there is no way this should be happening unless I really have shifted like I was thinking about last night. This shouldn't be possible since I didn't even use a method, but maybe if I look it up in this world I'll be able to figure this out. Either way, based on a really tiny Osamu Miya sleeping in the bottom bunk of what I can now see is a child's room, I definitely am nowhere near my dorm at Stanford.


	3. Don't. Freak. Out.

**Summary for the Chapter:**

> Chapters will likely be short and updates will probably be slow depending on my motivation. If you read the tags then you'll see that this is a self insert, and by that I mean I'm basically making an OC with a bit of my personality and my skills/talents (plus what I've reserched about a couple of different mental illnesses). It's also loosely based on my shifting script, so if Atsumu seems a bit OP with his skills then that's probably why. Also, as any other human, the OC will have flaws and make a lot of mistakes. Also in the tags, as the story progresses there will be heavy topics being introduced (such as what being completely ripped from your life and being in a completely different body can do to your mind). If that isn't your cup of tea then I suggest you stop following updates or reading the story. If you're still here by the end of this note, then enjoy the read and feel free to tell me your opinion (no matter how offending it may be).

Alright. I've got this. All I have to do, is act like a very young Atsumu Miya and find a way to get back home. Since actually seeing myself in the mirror confirmed this to be reality, I have to come up with a plan to trick the parents of the twins. This would be simple if not for the fact that I have no idea how Atsumu acted at this age, or what my parents names are, or even what they do. I really am going in here blind. Since it's the middle of the night, I should be able to explore the house with no issues. After that, I'll have to find an English-Japanese dictionary or something and hopefully learn the language by the time of Atsumu's next birthday. Oh my god I have so many things to do. I have to find that dictionary, figure out the date, somehow fool the parents, act completely different to myself, and find a way to get back home. In the slim chance that I actually do manage to get home within the year, I have to make sure that I don't ruin Atsumu's life, no matter how little time he actually got to live in it. Shit.. I'm probably going to have to get into mock fights with Osamu if I can't leave here quick enough. I really don't want to, both of them have been seen rolling on the floor and getting dirty more than once, and I'd really like to avoid that. I should've tried shifting into Sakusa instead. At least that way I'd be able to act out on my internal feelings and have Kimori by my side. I can't ever remember the Miya parents being mentioned in canon. Did they die? Did they just not care about their son's lives? Whether I liked it or not i know I'll have to find out soon enough as I'm currently in the body of their son. It kinda grosses me out just thinking about it. Where did the original Atsumu go? Did I erase his existence or something? 

_Stop_

There's no use thinking like that. Maybe when I leave everything will be back to normal, maybe it won't. If I keep thinking negatively, I know there is no way that I'm ever going to get out of here. I just need to stay calm and make a short term plan and a long term plan. Looking at the digital clock, I have six and a half hours until 7am. Hopefully no one here is an extremely early riser. Walking out of the bedroom, I'm greeted to a relatively modern house. There's a long hallway that connects the twin's room to their parents room, but it seems like the hall also connects to the living room. I'm not sure if the floor will creak at all, so I'll have to be extremely light on my feet. At least my gymnastics and dance training from when I was younger won't go to waste. Although it has been a number of years since... **it doesn't matter!** I just need to do everything to the best of my ability until I find a way back into my world. Until then, I'll only be able to do my best not to mess everything up in this one. 

__________________________________________________________________________________________________________________________________________________________________________________

The sunlight starting to peak in from the window reminds me to check the time. Finding my way back into the living room from the study, a quick glance at the red numbers proves the time to be 7:05. Damn it. I need to get back into the bedroom. Hopefully, everyone in the house will still be asleep and I'll get by undetected. As quickly and quietly as possible, I make my way back to the bedroom. I'm just about to open the door when the door to the master room opens. Dropping all subtlility, I quickly rip the door open and slam it shut. To make sure that I stay in character, I start poking Osamu's face. As long as we both are up the Miya parents shouldn't suspect a thing. They'll probably just think that we were trying to be sneaky and thought we got away with it due to... our.. young age. Damn that's so weird to say. Anyways, I was able to find a laptop, which should allow me to find everything else I need to get by in my new life. The display shows the date, July 28th, so I have a little less than three months to figure out the right rate of developement for a three going on four-year-old boy. I really got lucky, I honestly thought that everything would be in Japanese, considering where I am, but everything is easy to understand as if it was in English. Even the laptops display appears as English. Like I thought, really lucky because I only know the very basics of Japanese.

"'Sumu.. what'r you doin'.. 'm ti- tired."

What..? How was I able to understand that? There is a 0% chance that Osamu would wake up and start speaking in English. Even if I know some Japanese, there is no way I should be able to understand the Kansai accent. 

"Sumu! Stawp! I jus' wanna sleep, go 'way."

Oh... I'm panicking, I have no idea what I'm supposed to do. Do I just speak and hope it's in Japanese? What do I even say? Shit, damn it, ah. 

"Be quiet Samu! Ma an' pa will hear!"

Okay that works. That's something Atsumu would say right? Even if isn't, I doubt Osamu would notice. Suddenly, the door swings open, revealing the other Miyas. 

"Boys! What are you doing up so early? Are you already fighting? We could hear you from down the hall. Keep it down. We'll be going out, I'm sure that you can figure out your own breakfasts since you seem to be grown up enough to start shouting so early in the morning. Lets go."

Well I guess that's why their parents were never mentioned. They're just shitty people. Osamu's cries remind me that at the moment I am actually a child, and no child would want to be left behind by their parents. Good thing I've always been able to cry.

"NO! PLEASE! WE GOOD! PROMISE!" 

The father seems just about to reassure his crying children, as he should, when our.. oh wow, *our*, FOCUS! When our mother grabs him by the wrist and starts speaking again.

"No, you two were bad boys. That means you deserve to get punished. Yer father and I will be going out ter eat and you two will have teh think about what you've done. That's final."

The audacity of this woman. How fucking dare she? We are supposed to be three years old. Three. How does she expect three year olds to fend for themselves? What the actual hell. She gives one last nasty look before dragging our father out the door and into the car. Osamu is still crying and she didn't even bother to lock the door. I don't know if it's different here because it's a fictional universe, but people steal children who are home alone. We wouldn't be safe if I wasn't me. Then again, we probably wouldn't even be in this situation if it wasnt' for me. Have I ruined everything? Was this never supposed to happen? It was going to happen eventually, rig-

"Stupid 'Sumu! Ma hates us!"

Right, focus on your brother. Apparently I can understand verbal Japanese as well as I could verbel English. Later, I should check if that's the same for the alphabets too. Anyway, since our parents aren't home, I don't have to act any different to my usual self.

"Osamu, I'll make us both breakfast as long as you can keep a secret for me."

As long as I can convince him not to mention the behavior change to our parents, everything should be set for me to succeed. I might even be able to convince him to help me around so it seems like I've lived here my entire life. He could also be a valuable asset in the future in the case where I stay here for years.

"Promise?"

"I promise." 

"Okay... what's yer secret?"


End file.
